"Speech Sounds" and Parable of the Sower are both complex works, neither of which is reducible to a single point or sequence of points. However, there are clear thematic and structural similarities between the two. Both portray violent societies in a state of collapse, with the structures and certainties of civilization crumbling, forcing the characters to fend for themselves. In both texts, communication is of paramount importance. "Speech Sounds" is the shorter and simpler text, solving the problem of communication with the simple speech that has fallen into desuetude as civilization has crumbled in the wake of a devastating pandemic. In Parable of the Sower, Lauren creates a new religion to communicate what is needed to survive in a society that no longer finds any relevance in traditional Christianity. Explaining the principles of Earthseed requires the greater length and capacity for discursiveness that only a novel can provide.
Butler focuses on the importance of human connection. Both story and novel depict societies which have become broken and violent because the ties of civil society and community no longer exist. People are frightened and prey upon one another. In each case, the protagonist must take risks to form connections with other people, but this is the only way to survive and flourish in the long term. In "Speech Sounds," caring for the children reestablishes Rye's neglected identity as a teacher and a protector, while in Parable of the Sower, Lauren is able to establish an oasis of peace in a community dedicated to the principles of Earthseed.